why do people/game journelists keep calling mario a casual game?

[Nick]

Mummelmann said:
Mario is quite casual, I remember my mom and one of my aunts used to stay up all night playing SMB 2 and 3 and Duck Hunt. Why is it so bad that someone calls it casual (or calls a shovel a shovel)?
It attracts both casual and "hardcore" gamers and that equals a lot more sales. And that's a good thing, right? So what's with the complaining over this?

If they stayed up all night playing it then they weren't playing it casually.  Just because they're your mom and aunt doesn't automatically mean they can't be playing a game in a hardcore manner.